This application claims the benefit of Korean Application No. 2002-33085, filed Jun. 14, 2002, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a microwave oven, and more particularly, to a cooking shelf for a microwave oven and a microwave oven having the same, which is adapted to support food and to allow heat radiated from heaters of the microwave oven to be applied to the food.
2. Description of the Related Art
In general, a microwave oven is an electrical appliance to cook food disposed in its cooking chamber with high-frequency electromagnetic waves generated from a magnetron. In recent years, the microwave oven has been provided with a heater in the cooking chamber to carry out a cooking operation by heat from the heater, as well as high-frequency electromagnetic waves from a magnetron, thereby improving a cooking effect.
As shown in FIG. 1, a microwave oven includes a heater 2 positioned at an upper level of a cooking chamber 1, and a tray 3 placed on a bottom of the cooking chamber 1 on which food is placed. The cooking chamber 1 is externally provided at its bottom with a motor 4 to rotate the tray 3. When a cooking operation by the heater 2 is carried out, a cooking shelf 5 is placed on the bottom of the cooking chamber 1 to raise a level of food xe2x80x9cF,xe2x80x9d so that heat from the heater 3 is effectively transmitted to the food xe2x80x9cF.xe2x80x9d
However, since the heater 2 is positioned at the upper level of the cooking chamber 1, heat radiated from the heater 2 is largely applied to upper portions of the food xe2x80x9cFxe2x80x9d. Hence, there is an inconvenience in that the food xe2x80x9cFxe2x80x9d placed on the cooking shelf 5 must be turned over during cooking in order to equally cook lower portions of the food xe2x80x9cF.xe2x80x9d
To overcome the above inconvenience, microwave ovens have been developed to have heaters at its upper and lower levels, so that upper and lower portions of food xe2x80x9cFxe2x80x9d are equally heated by the upper and lower heaters. However, since the lower heater cannot be close to lower portions of the food xe2x80x9cFxe2x80x9d because of the configuration of the cooking shelf, a cooking effect of the lower portions of the food xe2x80x9cFxe2x80x9d is not satisfactory.
As shown in FIG. 2, a conventional cooking shelf 5 for a microwave oven includes a grill plate 5a on which food xe2x80x9cFxe2x80x9d is placed, and a plurality of support legs 5b downwardly extended from a peripheral edge of the grill plate 5a. Since the cooking shelf 5 is mounted on the tray 3 and rotated together with the tray 3, it is difficult to position the support legs 5b below the grill plate Sa, thereby limiting the cooking effect of the food xe2x80x9cFxe2x80x9d.
Accordingly, it is an object of the present invention to provide a cooking shelf for a microwave oven and a microwave oven having the same, which is adapted to allow upper and lower heaters of the microwave oven to be equally close to food, so that the food is equally broiled at upper and lower portions of the food.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing a cooking shelf for a microwave oven, which is used in a cooking chamber of the microwave oven to cause food placed thereon to be close to a heater. The cooking shelf includes an upper shelf part having a certain area on which food is placed, a column part, which is downwardly extended from the upper shelf part by a certain length to support the upper shelf part, and a lower support part which is connected to a lower end of the column part and radially extended to support the column part.
According to an aspect of the invention, the upper shelf part includes an upper grill plate and a plurality of reinforcing arms, which are attached to a lower surface of the upper grill plate and radially extended from a center of the upper grill plate.
According to an aspect of the invention, the column part is downwardly bent at and downwardly extended from radial inner ends of the reinforcing arms.
According to an aspect of the invention, the lower support part includes a plurality of support legs, which are extended radially and outwardly from the lower end of the column part.
According to another aspect of the invention, the lower support part includes an annular retaining ring attached thereto to support the plurality of support legs.
According to another aspect of the invention, the lower support part includes a lower grill plate attached to the support legs, on which food is placed.
According to yet another aspect of the invention, the support legs are provided at their outer ends with extensions, which are extended downwardly by a certain length to cause the lower support part to be spaced from a bottom surface of the cooking chamber.
The foregoing and other objects of the present invention are achieved by providing a microwave oven including an oven body defining an exterior appearance of the microwave oven, a cooking chamber provided in the oven body, an upper heater disposed in the cooking chamber to be positioned at an upper level of the cooking chamber, and a lower heater disposed in the cooking chamber to be positioned at a lower level of the cooking chamber. The microwave oven also includes a cooking shelf disposed in the cooking chamber to cause food placed thereon to be positioned between the upper and lower heater. The cooking shelf includes an upper shelf part having a certain area on which food is placed, a column part, which is downwardly extended from the upper shelf part by a certain length to support the upper shelf part, and a lower support part which is connected to a lower end of the column part and radially extended to support the column part.
According to an aspect of the invention, the cooking chamber includes a rotatable tray at a bottom of the cooking chamber, on which the cooking shelf is mounted, and in which the column part is downwardly extended from a rotational axis of the upper shelf part so that the cooking shelf does not interfere with the lower heater when the cooking shelf is rotated.